This circuit was originally designed to measure capacitance with an ICL7107 but can be used with other digital modules. The circuit is from Electronics Now magazine from November 1996.
This circuit was indicated in an old American publication to serve as a Laser alarm system as a...
This circuit, which uses only transistors as active components, was found in a 1987 documentation. The...
This sound meter or sonometer was found in a Popular Electronics from the 80's. The circuit can be...